There are three different Building Code: H1, G7 and E3
H1 Energy Efficiency
Provides for the efficient use of energy and sets physical conditions for energy performance.
This clause requires housing to meet a building performance index (BPI) not exceeding 1.55 (this is defined in the Verification Method and Acceptable Solution).
It requires enclosed spaces where temperature or humidity are modified to provide adequate thermal resistance and to limit uncontrollable airflow in certain buildings. It also sets out physical conditions likely to affect energy performance, and requirements for hot water systems, artificial lighting and HVAC systems.
G7 Natural Light
Providing sufficient natural light for occupied spaces and appropriate visual awareness of the outside for occupants.
This clause requires habitable spaces to have adequate windows for natural light and visual awareness of the outside environment to safeguard against illness, and loss of amenity due to isolation.
It requires natural light of no less than 30 lux at floor level for 75% of the standard year, and for transparent openings in certain buildings.
E3 Internal Moisture
Surfaces in wet areas must be impervious, easily cleaned, and have ventilation to meet conditions for health and safety.
This Building Code clause requires buildings to be constructed to avoid fungal growth and excessive moisture. Its provisions relate to habitable spaces, bathrooms, laundries and other spaces where moisture may be generated or accumulate.
Its requirements include provisions for:
adequate thermal resistance
disposal of overflow water
surfaces to be impervious and easily cleaned.